Whedon pits hero against hero against villain in one of the smartest, funniest, and most exciting action movies in the last few decades.

Over the last half decade, Marvel has embarked on a massive superhero journey, explaining over half a dozen films the origins of the Avengers, a superhero supergroup comprised of Captain America (Chris Evans), Iron Man (Robert Downey, Jr.), Thor (Chris Hemsworth), The Hulk (Mark Ruffalo replacing Edward Norton), Black Widow (Scarlett Johansson), and Hawkeye (Jeremy Renner). No matter your thoughts on the preceding movies (Iron Man 2 was not very good and Thor was stupid but fun), you’re bound to adore this weekend’s brilliant culmination, the Joss Whedon nerdfest – and I mean that in the best way – The Avengers.

When fans heard Whedon might be connected to this movie, much rejoicing was heard across the internet. This is the man who brought you “Buffy the Vampire Slayer,” “Firefly,” and Serenity. Whedon is a bloody genius with ensemble casts and witty, intelligent dialogue – which tells you all you really need to know about The Avengers. Obviously I’m going to continue, because that’s what I’m here for – but first and foremost know that the film’s screenplay is nothing short of brilliant.

There’s no slow build to action in The Avengers. In the opening moments Nick Fury (Samuel L. Jackson, of whom we caught a glimpse post-credits in Iron Man 2) debarks from an aircraft with his assistant, Agent Hill (Cobie Smulders), and we’re thrown into world-in-jeopardy action from the first five minutes. Dr. Selvig (Stellan Skarsgård) has been assisting S.H.I.E.L.D., an international peacekeeping organization, to build a pipeline from space through which clean energy will flow like manna from heaven. Ostensibly. Unfortunately, at the end of the pipeline is, well, outer space. And who should be attracted to this open door like a moth to flame, but Loki (Tom Hiddleston), brother of Thor and son of Odin, who is poised to take his “rightful” place as ruler of earth. Loki, a boy king, petulant, cruel, and vengeful, will force the people of earth to bow to him; after all, we are made to be ruled. After a short, gripping battle, Loki escapes after veritably hypnotizing Hawkeye and Selvig.

“As of this moment, we are at war,” Fury says solemnly, and Fury closes his metaphorical fist, bringing together all our major players. Dr. Bruce Banner, who hasn’t had a “Hulk smash” incident in over a year, is treating the sick in Calcutta. Tony Stark is living in bliss with Pepper Potts (Gwyneth Paltrow) in the upper floors of Stark’s latest, greatest monument to himself, Stark Tower. Natasha Romanoff is doing what she does best – interrogation – in Russia. Steve Rogers, awakened after 70 years trapped in ice, has no idea what to do with himself so demolishes punching bags and mourns the death of his sweetheart. Fury sends Agent Phil Coulson (Clark Gregg) to gather the unwilling, largely unstable troops and load them aboard the helicarrier. After the earthbound heroes track down Loki, Thor pops in from the heavens to try to save the day on his own terms – which of course irks the mortals.

What follows is what we’ve really been waiting for; we didn’t pay to see how the superheroes band together – no, we want to see them fight each other. Of course, each battle between our reluctant heroes is better than the last – and they aren’t simply thrown together Mortal Kombat-style for the sake of box office dollars. Authentic, clever dialogue segues into the superhero equivalent of fisticuffs. This is where Whedon excels – he gives his casts, no matter how large, generous character development. His actors seem to have ample time to step comfortably into their characters. In the case of The Avengers, these guys are military experiments, radiation survivors, supergeniuses, and demigods. Each feels vastly different from the others about his position in the world. With egos this big, something’s bound to come undone – but in Whedon’s hands, it’s not only a pleasure to watch the interactions between our heroes, it’s also absurdly exciting.

In a further twist, it turns out S.H.I.E.L.D. isn’t actually in this battle for anything so innocent as clean energy; WMDs are the name of the game. “A nuclear deterrent,” as Stark says, “’cause that always calms everything down.” After Loki escapes his cage, scattering the Avengers to the four winds and murdering a secondary but beloved player, the heroes have a reason to fight. An army from outer space soars through a portal over New York City, and the S.H.I.E.L.D’s Council sends orders to nuke Manhattan. What are heroes for, if not to save the world? Ours do just that in stylish, exhilarating fashion, punctuating the BOPs and WHAMs and roars with hilarious discourse.

Not to compare actors to superheroes, but this cast could easily have exploded in our faces; like their characters, each of these actors is famous in his or her own right. Some are A-list while others hover just below, and it takes a persuasive genius (shall we call Whedon a Nick Fury of sorts?) to gather them and get them to fight for a common cause. Rumor has it Edward Norton’s ego was a bit too large to join this cast, but that’s fine. Ruffalo makes a perfect Banner and a great Hulk. Evans is charmingly earnest, delivering more in facial expressions than with lines. Downey, Jr. spouts dozens of one-liners that still have me chuckling fourteen hours later. Johansson and Renner play out a complex, tense relationship with subtle ease. Hemsworth is certainly a pretty face – though sorry, ladies, no shirtless Thor this time around – but he plays Thor comfortably and with a lack of humor that makes the character that much funnier. Hiddleston inhabits Loki with a frightening glee – the kind you associate with a future psychopath roasting ants with a magnifying glass. Yet every actor metaphorically doffs his hat to the next; you’ll see no scenery-chewing or one-up-manship in The Avengers. These guys genuinely play nice together, and that’s the key to a great ensemble cast.

For Whedon fans and comic aficionados alike, The Avengers is a nerdgasm, a playful and intelligent opening to the summer movie season (and be sure to stick around for a few minutes into the credits for a peek at the next step in the franchise). This year is going to be a doozie – before The Avengers, you’ll see new trailers for The Dark Knight Rises, Prometheus, The Amazing Spider-Man, Battleship, Brave, and Frankenweenie – in other words, all the big movies about which we movie nerds are preliminarily salivating. If The Avengers is any indication, this summer in theaters going to be nothing short of breathtaking.